Two numbers on a peptide spec sheet are easy to mix up: purity and net peptide content. They measure different things. Understanding both tells you how much actual peptide is in the vial. Here’s the difference.
- Purity (HPLC): what fraction of the peptide material is the target peptide.
- Net peptide content: what fraction of the vial’s total weight is actually peptide.
- The rest of the weight is water, salts and counterions.
The difference
HPLC purity compares the target peptide against other peptide-related impurities. Net peptide content is different: a freeze-dried vial also contains bound water and salt counterions, so not 100% of the powder’s weight is peptide. Net content tells you how much truly is.
| Purity (HPLC) | Net peptide content | |
|---|---|---|
| Measures | Target vs impurities | Peptide vs total weight |
| Accounts for salts/water? | No | Yes |
Both appear on a thorough Certificate of Analysis. For most in vitro research, knowing both helps you work accurately.
Research use only. For educational purposes. Compounds referenced are sold strictly for in vitro laboratory research by qualified professionals.
Every batch we sell is purity-verified
Third-party Certificates of Analysis on each lot.